Air heater



G. TURKUS June 30,- 1 931.

AIR HEATER Filed y 1928 2 Sheets-Sheet l EINVENTOR BY 5 W M W ATTORNEYS June 30, 1931.

G. TURKUS AIR HEATER Filed July 20. 1928 heats-Sheet 2 00 I I l oooooooooooooooo o0 I 000 000 00 l 000 00 00 f I oo o o o o g I "I I O O o o o l I o a 0i 0 0 Sii' 8 8 8; 2 o l ,0 o o i o o o I I o e o o o INVENTOR @47 M44 BY 49' M/ZML ATTORNEY6 Patented June so, 1931 UNITED STATES PATENT' OFFICE GEORGE TURKUS, OF LONDON, ENGLAND, .A SSIGNOB 1'0 BAIBCOGK & WILGOX OOIPANY,

' OF NEW YORK, N. Y.

Am HEATER I Appldcation flled July 20, 1928, Serial No. 294,259, and in Great'IBritain My 26, 1827.

This invention relates to improvements in air heaters of the type in which the hot gases travel through tubes or ducts whlle the air passes over the outer surfaces of such 6 tubes or ducts, and is applicable to heaters of contra-flow, of parallel and of mixed flow design. The invention has for an object to permit of obtaining by means of one and the same air heater air at two or more dif- 1 ferent temperatures.

With this object in view in accordance with the invention, at points spaced in relation to the flow of the air-there are provided in the casin of the air heater damper-con trolled opemngs through which a fraction or fractions of the volume ofair being heated may be drawn off. The entire volume of air enters. the heater at one point and flows over the heating surface to'the point where it has become heated to the lowest of the several required temperatures, at this latter point, the first bleeding point, the quantity of air re uired at that temperature is led ofi throug a damper-controlled opening or openings, the remainder of the air flowing over the heating surface to the point where it has become heated to the next higher of the several required temperatures, i. e. the

second bleeding point where the quantit air re uired at that temperature is led throug ing, the remainin air flowing'over the farther heating sur ace and the vfractions of the total air quantity required at the various proper points. i

In order toobtain advantageous rates of heat transmission throughout the air heater notwithstanding that the quantities of air passing over different parts of the heater are unequal the cross-sectional areas of the air passages in the several parts of the heater are made unequal by disposing the transverse air-baflles at unequal distances apart, these-distances. being largest 'for the first sta e 1am? smallest for the last stagefrom the last bleeding pointito the point where the last fraction of air leaves the heater. In a duplex air heater contrived'to proof off a second damper-controlled open-' higher temperatures being led off at the.-

in advance of the first bleeding point vide a main supply of heated air and a supply of secondary air of much higher temperature an outlet passage fitted with a damper may be provided at the outer side of each heater unit adjacent to the last pass for the main air suppl a common air with- ."drawal duct fitted wit a damper connected with the final pass of each heater providing the secondary air supply.

The invention is illustrated diagrammatically in the accompanying drawings in which Fig. 1 is a vertical sectional view of a single air heater in accordance with the invention by which air is obtained at different temperatures; while Fig. 2 is a vertical sectional view of an air heater with central.

air'passages in which a small fraction of the total volume of air herein referred to as seconda air is heated to a temperature exceeding t e .temperature of the primary air supply, Fig. 3 is a cross sectional view 'taken' through the heater of Fig. 1 and Fig.

4 is a cross sectional. view taken throughithe "heater of Fig. 2.

heater at oand flows over the heating sure face to the point d where it has become heated to the lowest of the several'required dampers dwhilst the remainder of the air temperatures. At this point the quantity of flows overthe heating surfaceto the point e where it has become heatedto the next high- 3 er of the several required temperatures, when the quantity of air required at that temperature is taken awaythrough a second opening e controlled by dampers. e, the remaining air-flowin over the further heat ing surface to the points f and 9' where fractions at higher temperatures are drawn of.

In order to obtain advantageous rates of heat transmission throughoutthe air heater notwithstanding that the quantities of air passing over. various parts of the heater are unequal the cross-sectional areas of the air passages h, 2', lo and Z in successive parts of the heater are made unequal by disposing the-transverse air baflles m at unequal distances apart, these distances being. largest betweenc and d and smallest between f and g.

In the embodiment shown in Fig. 2 in tended to provide a main supply of heated air and a supply of secondary air' and in which as before a indicates the gas inlet, 6 the gas outlet ando the air inlet, an air outlet passage 03 fitted with a damper m is prov vided at the outer side of each'heate-r and adjacent to the last pass for the main air supply, a common air withdrawal duct or outlet duct m fitted with a damper 1? connected with the final pass of each heater leading ofi the secondary air supply.

I claim,

1. An air heater adapted to be heated by hot lgases-comprising ducts for the passage of t 0 hot gases and air passages for the flow of the air around said ducts, said air passages formed with an outlet opening intermediate the air inlet and outlet at a point spaced in relation to the flow of the air, and

a damper controlling such openings.

2. An air'heater comprising ducts for the passage of the hot gases and air passages around said ducts for the passage of air to be heated, said air passages being-constituted by baflies spaced unequally apart, said airpassages formedwith an outlet opening and a damper controlling such openings.

3. An air heater comprising a pair of juxtaposed heaters each comprising gas ducts, a plurality of air passes around said ducts and an air inlet common to both, an

outlet opening in the last pass of each heater, a damper controlling each such outlet, and an outlet common to bothheaters and connected with the last pass of each heater, said last-mentioned outlet also fitted with a damper, substantially as and for the purpose set forth;

4. In an air heater, a passageway for hot gases, means for causing air to flow across said passageway a plurality of times in sue-- session, and anoutlet for the air at a point intermediate its traverses across said passageway.

'5. In an air heater, a passageway for hot Qgases, means for causing air to flow'across ;sa1d passageway a pluralltyof tlmes 1n successlon, through paths whose cross sectional ia'reas decrease successively, andian outlet qfortheair at a point intermediate its L 'ersesv across said passageway. testimony nameto;thisspecification. 7 37 GEORGE TURKUS.

whereof I have signed my trav V 

